Periodic Table > Aluminium
 

Terminology


Allotropes
Some elements exist in several different structural forms, these are called allotropes.


For more information on Murray Robertson’s image see Uses and properties facts below.

 

Fact box terminology


Group
Elements appear in columns or ‘groups’ in the periodic table. Members of a group typically have similar properties and electron configurations in their outer shell.


Period
Elements are laid out into rows or ‘periods’ so that similar chemical behaviour is observed in columns.


Block
Elements are organised into blocks by the orbital type in which the outer electrons are found. These blocks are named for the characteristic spectra they produce: sharp, principal, diffuse, and fundamental.


Atomic Number
The number of protons in the nucleus.


Atomic Radius/non -bonded (Å)
based on Van der Waals forces (where several isotopes exist, a value is presented for the most prevalent isotope). These values were calculated using a multitude of methods including crystallographic data, gas kinetic collision cross sections, critical densities, liquid state properties, for more details please refer to the CRC Handbook of Chemistry and Physics.


Electron Configuration
The arrangements of electrons above the last (closed shell) noble gas.


Isotopes
Elements are defined by the number of protons in its centre (nucleus), whilst the number of neutrons present can vary. The variations in the number of neutrons will create elements of different mass which are known as isotopes.


Melting Point (oC)
The temperature at which the solid-liquid phase change occurs.


Melting Point (K)
The temperature at which the solid-liquid phase change occurs.


Melting Point (oF)
The temperature at which the solid-liquid phase change occurs.


Boiling Point (oC)
The temperature at which the liquid-gas phase change occurs.


Boiling Point (K)
The temperature at which the liquid-gas phase change occurs.


Boiling Point (oF)
The temperature at which the liquid-gas phase change occurs.


Sublimation
Elements that do not possess a liquid phase at atmospheric pressure (1 atm) are described as going through a sublimation process.


Density (kgm-3)
Density is the weight of a substance that would fill 1 m3 (at 298 K unless otherwise stated).


Relative Atomic Mass
The mass of an atom relative to that of Carbon-12. This is approximately the sum of the number of protons and neutrons in the nucleus. Where more than one isotope exists the value given is the abundance weighted average.


Key Isotopes (% abundance)
An element must by definition have a fixed number of protons in its nucleus, and as such has a fixed atomic number, however variants of an element can exist with differing numbers of neutrons, and hence a different atomic masses (e.g. 12C has 6 protons and 6 neutrons and 13C has 6 protons and 7 neutrons).


CAS number
The Chemical Abstracts Service registry number is a unique identifier of a particular chemical, designed to prevent confusion arising from different languages and naming systems (where several isotopes exist, a value is presented for the most prevalent isotope).

Fact box

 
Group 13  Melting point 660.323 oC, 1220.581 oF, 933.473 K 
Period Boiling point 2519 oC, 4566.2 oF, 2792.15 K 
Block Density (kg m-3) 2698 
Atomic number 13  Relative atomic mass 26.982  
State at room temperature Solid  Key isotopes 27Al 
Electron configuration [Ne] 3s23p1  CAS number 7429-90-5 
ChemSpider ID 4514248 ChemSpider is a free chemical structure database
 

Uses and properties terminology


Image Explanation

Murray Robertson is the artist behind the images which make up Visual Elements. This is where the artist explains his interpretation of the element and the science behind the picture.


Natural Abundance

Where this element is most commonly found in nature.


Biological Roles

The elements role within the body of humans, animals and plants. Also functionality in medical advancements both today and years ago.


Appearance

The description of the element in its natural form.

Uses and properties

 
Image explanation
Aircraft fuselages and aluminium foil are just two of the many and varied uses of this element
Appearance

Aluminium is a silvery-white, lightweight metal. It is soft and malleable.

Uses

Aluminium is used in a huge variety of products including cans, foils, kitchen utensils, window frames, beer kegs and aeroplane parts. This is because of its particular properties. It has low density, is non-toxic, has a high thermal conductivity, has excellent corrosion resistance and can be easily cast, machined and formed. It is also non-magnetic and non-sparking. It is the second most malleable metal and the sixth most ductile.

 

It is often used as an alloy because aluminium itself is not particularly strong. Alloys with copper, manganese, magnesium and silicon are lightweight but strong. They are very important in the construction of aeroplanes and other forms of transport.

 

Aluminium is a good electrical conductor and is often used in electrical transmission lines. It is cheaper than copper and weight for weight is almost twice as good a conductor.

 

When evaporated in a vacuum, aluminium forms a highly reflective coating for both light and heat. It does not deteriorate, like a silver coating would. These aluminium coatings have many uses, including telescope mirrors, decorative paper, packages and toys.

Biological role
Aluminium has no known biological role. In its soluble +3 form it is toxic to plants. Acidic soils make up almost half of arable land on Earth, and the acidity speeds up the release of Al3+ from its minerals. Crops can then absorb the Al3+ leading to lower yields.

Our bodies absorb only a small amount of the aluminium we take in with our food. Foods with above average amounts of aluminium are tea, processed cheese, lentils and sponge cakes (where it comes from the raising agent). Cooking in aluminium pans does not greatly increase the amount in our diet, except when cooking acidic foods such as rhubarb. Some indigestion tablets are pure aluminium hydroxide.

Aluminium can accumulate in the body, and a link with Alzheimer’s disease (senile dementia) has been suggested but not proven.
Natural abundance

Aluminium is the most abundant metal in the Earth’s crust (8.1%) but is rarely found uncombined in nature. It is usually found in minerals such as bauxite and cryolite. These minerals are aluminium silicates.

Most commercially produced aluminium is extracted by the Hall–Héroult process. In this process aluminium oxide is dissolved in molten cryolite and then electrolytically reduced to pure aluminium. Making aluminium is very energy intensive. 5% of the electricity generated in the USA is used in aluminium production. However, once it has been made it does not readily corrode and can be easily recycled.

 
Atomic data terminology

Atomic radius/non -bonded (Å)
Based on Van der Waals forces (where several isotopes exist, a value is presented for the most prevalent isotope). These values were calculated using a multitude of methods including crystallographic data, gas kinetic collision cross sections, critical densities, liquid state properties,for more details please refer to the CRC Handbook of Chemistry and Physics.


Electron affinity (kJ mol-1)
The energy released when an additional electron is attached to the neutral atom and a negative ion is formed (where several isotopes exist, a value is presented for the most prevalent isotope). *


Electronegativity (Pauling scale)
The degree to which an atom attracts electrons towards itself, expressed on a relative scale as a function bond dissociation energies, Ed in eV. χA - χB =(eV)-1/2sqrt(Ed(AB)-[Ed(AA)+Ed(BB)]/2), with χH set as 2.2 (where several isotopes exist, a value is presented for the most prevalent isotope).


1st Ionisation energy (kJ mol-1)
The minimum energy required to remove an electron from a neutral atom in its ground state (where several isotopes exist, a value is presented for the most prevalent isotope).


Covalent radius (Å)
The size of the atom within a covalent bond, given for typical oxidation number and coordination (where several isotopes exist, a value is presented for the most prevalent isotope). ***

Atomic data

 
Atomic radius, non-bonded (Å) 1.840 Covalent radius (Å) 1.24
Electron affinity (kJ mol-1) 41.747 Electronegativity
(Pauling scale)
1.610
Ionisation energies
(kJ mol-1)
 
1st
577.539
2nd
1816.677
3rd
2744.779
4th
11577.459
5th
14841.845
6th
18379.477
7th
23326.276
8th
27465.493
 

Mining/Sourcing Information

Data for this section of the data page has been provided by the British Geological Survey. To review the full report please click here or please look at their website here.


Key for numbers generated


Governance indicators

1 (low) = 0 to 2

2 (medium-low) = 3 to 4

3 (medium) = 5 to 6

4 (medium-high) = 7 to 8

5 (high) = 9


Reserve base distribution

1 (low) = 0 to 30 %

2 (medium-low) = 30 to 45 %

3 (medium) = 45 to 60 %

4 (medium-high) = 60 to 75 %

5 (high) = 75 %

(Where data are unavailable an arbitrary score of 2 was allocated. For example, Be, As, Na, S, In, Cl, Ca and Ge are allocated a score of 2 since reserve base information is unavailable. Reserve base data are also unavailable for coal; however, reserve data for 2008 are available from the Energy Information Administration (EIA).)


Production Concentration

1 (low) = 0 to 30 %

2 (medium-low) = 30 to 45 %

3 (medium) = 45 to 60 %

4 (medium-high) = 60 to 75 %

5 (high) = 75 %


Crustal Abundance

1 (low) = 100 to 1000 ppm

2 (medium-low) =10 to 100 ppm

3 (medium) = 1 to 10 ppm

4 (medium-high) = 0.1 to 1 ppm

5 (high) = 0.1 ppm

(Where data are unavailable an arbitrary score of 2 was allocated. For example, He is allocated a score of 2 since crustal abundance data is unavailable.)


Explanations for terminology


Crustal Abundance (ppm)

The abundance of an element in the Earth's crust in parts-per-million (ppm) i.e. The number of atoms of this element per 1 million atoms of crust.


Sourced

The country with the largest reserve base.


Reserve Base Distribution

This is a measure of the spread of future supplies, recording the percentage of a known resource likely to be available in the intermediate future (reserve base) located in the top three countries.


Production Concentrations

This reports the percentage of an element produced in the top three countries. The higher the value, the larger risk there is to supply.


Total Governance Factor

The World Bank produces a global percentile rank of political stability. The scoring system is given below, and the values for all three production countries were summed.


Relative Supply Risk Index

The Crustal Abundance, Reserve Base Distribution, Production Concentration and Governance Factor scores are summed and then divided by 2, to provide an overall Relative Supply Risk Index.

Supply risk

 
Scarcity factor 3.5
Country with largest reserve base Guinea
Crustal abundance (ppm) 84149
Leading producer Australia
Reserve base distribution (%) n/a
Production concentration (%) 33.10
Total governance factor(production) 6
Top 3 countries (mined)
  • 1) Guinea
  • 2) Australia
  • 3) Vietnam
Top 3 countries (production)
  • 1) Australia
  • 2) China
  • 3) Brazil
 

Oxidation states and isotopes


Key for Isotopes


Half Life
  y years
  d days
  h hours
  m minutes
  s seconds
Mode of decay
  α alpha particle emission
  β negative beta (electron) emission
  β+ positron emission
  EC orbital electron capture
  sf spontaneous fission
  ββ double beta emission
  ECEC double orbital electron capture

Terminology


Common Oxidation states
The oxidation state of an atom is a measure of the degree of oxidation of an atom. It is defined as being the charge that an atom would have if all bonds were ionic. Free atoms have an oxidation state of 0, and the sum of oxidation numbers within a substance must equal the overall charge.


Important Oxidation states
The most common oxidation states of an element in its compounds.


Isotopes
Elements are defined by the number of protons in its centre (nucleus), whilst the number of neutrons present can vary. The variations in the number of neutrons will create elements of different mass which are known as isotopes.

Oxidation states and isotopes

 
Common oxidation states 3
Isotopes Isotope Atomic mass Natural abundance (%) Half life Mode of decay
  27Al 26.982 100
 

Pressure and temperature - advanced terminology


Molar Heat Capacity (J mol-1 K-1)

Molar heat capacity is the energy required to heat a mole of a substance by 1 K.


Young's modulus (GPa)

Young's modulus is a measure of the stiffness of a substance, that is, it provides a measure of how difficult it is to extend a material, with a value given by the ratio of tensile strength to tensile strain.


Shear modulus (GPa)

The shear modulus of a material is a measure of how difficult it is to deform a material, and is given by the ratio of the shear stress to the shear strain.


Bulk modulus (GPa)

The bulk modulus is a measure of how difficult to compress a substance. Given by the ratio of the pressure on a body to the fractional decrease in volume.


Vapour Pressure (Pa)

Vapour pressure is the measure of the propensity of a substance to evaporate. It is defined as the equilibrium pressure exerted by the gas produced above a substance in a closed system.

Pressure and temperature data – advanced

 
Molar heat capacity
(J mol-1 K-1)
24.2 Young's modulus (GPa) Unknown
Shear modulus (GPa) Unknown Bulk modulus (GPa) Unknown
Vapour pressure  
Temperature (K)
400 600 800 1000 1200 1400 1600 1800 2000 2200 2400
Pressure (Pa)
1.21
x 103
1.36
x 103
1.54
x 103
1.78
x 103
2.09
x 103
- - - - - 2.52
x 103
  Help text not available for this section currently

History

The analysis of a curious metal ornament found in the tomb of Chou-Chu, a military leader in 3rd century China, turned out to be 85% aluminium. How it was produced remains a mystery. By the end of the 1700s, aluminium oxide was known to contain a metal, but it defeated all attempts to extract it. Humphry Davy had used electric current to extract sodium and potassium from their so-called ‘earths’ (oxides), but his method did not release aluminium in the same way. The first person to produce it was Hans Christian Oersted at Copenhagen, Denmark, in 1825, and he did it by heating aluminium chloride with potassium. Even so, his sample was impure. It fell to the German chemist Friedrich Wöhler to perfect the method in 1827, and obtain pure aluminium for the first time by using sodium instead of potassium.

  Help text not available for this section currently

Podcasts

Listen to Aluminium Podcast
Transcript :

Chemistry in Its Element - Aluminium


 

  (Promo)

 

You're listening to Chemistry in its element brought to you by Chemistry World, the magazine of the Royal Society of Chemistry

(End promo)

 

Chris Smith

This week the chemical cause of transatlantic linguistic friction.   Is it an um or an ium at the end? It turns out us Brits might have egg on our faces as well as a liberal smattering of what we call aluminium.

 

Kira J. Weissman

'I feel like I'm trapped in a tin box at 39000 feet'.   It's a common refrain of the flying-phobic, but maybe they would find comfort in knowing that the box is actually made of aluminium - more than 66000 kg of it, if they're sitting in a jumbo jet.   While lamenting one's presence in an 'aluminium box' doesn't have quite the same ring, there are several good reasons to appreciate this choice of material.   Pure aluminium is soft.   However, alloying it with elements such as such as copper, magnesium, and zinc, dramatically boosts its strength while leaving it lightweight, obviously an asset when fighting against gravity.   The resulting alloys, sometimes more malleable than aluminium itself, can be moulded into a variety of shapes, including the aerodynamic arc of a plane's wings, or its tubular fuselage.   And whereas iron rusts away when exposed to the elements, aluminium forms a microscopically thin oxide layer, protecting its surface from further corrosion.   With this hefty CV, it's not surprising to find aluminium in many other vehicles, including ships, cars, trucks, trains and bicycles.

 

Happily for the transportation industry, nature has blessed us with vast quantities of aluminium.   The most abundant metal in the earth's crust, it's literally everywhere.   Yet aluminium remained undiscovered until 1808, as it's bound up with oxygen and silicon into hundreds of different minerals, never appearing naturally in its metallic form.   Sir Humphrey Davy, the Cornish chemist who discovered the metal, called it 'aluminum', after one of its source compounds, alum.   Shortly after, however, the International Union of Pure and Applied Chemistry (or IUPAC) stepped in, standardizing the suffix to the more conventional 'ium'.   In a further twist to the nomenclature story, the American Chemical Society resurrected the original spelling in 1925, and so ironically it is the Americans and not the British that pronounce the element's name as Davy intended.

 

In 1825, the honour of isolating aluminium for the first time fell to the Danish Scientist Hans Christian Øersted.   He reportedly said of his prize, 'It forms a lump of metal that resembles tin in colour and sheen" - not an overly flattering description, but possibly an explanation for airline passengers' present confusion.   The difficulty of ripping aluminium from its oxides - for all early processes yielded only kilogram quantities at best - ensured its temporary status as a precious metal, more valuable even than gold.   In fact, an aluminium bar held pride of place alongside the Crown Jewels at  the 1855 Paris Exhibition, while Napoleon is said to have reserved aluminium tableware for only his most honoured guests.

It wasn't until 1886 that Charles Martin Hall, an uncommonly dogged, amateur scientist of 22, developed the first economic means for extracting aluminium.   Working in a woodshed with his older sister as assistant, he dissolved aluminium oxide in a bath of molten sodium hexafluoroaluminate (more commonly known as 'cryolite'), and then pried the aluminium and oxygen apart using a strong electrical current.    Remarkably, another 22 year-old, the Frenchman Paul Louis Toussaint Héroult, discovered exactly the same electrolytic technique at almost exactly the same time, provoking a transatlantic patent race.   Their legacy, enshrined as the Hall-Héroult process, remains the primary method for producing aluminium on a commercial scale - currently million of tons every year from aluminium's most plentiful ore, bauxite.  

 

It wasn't only the transportation industry that grasped aluminium's advantages.   By the early 1900s, aluminium had already supplanted copper in electrical power lines, its flexibility, light weight and low cost more than compensating for its poorer conductivity.    Aluminium alloys are a construction favourite, finding use in cladding, windows, gutters, door frames and roofing, but are just as likely to turn up inside the home: in appliances, pots and pans, utensils, TV aerials, and furniture.   As a thin foil, aluminium is a packaging material par excellence, flexible and durable, impermeable to water, and resistant to chemical attack - in short, ideal for protecting a life-saving medication or your favourite candy bar.   But perhaps aluminium's most recognizable incarnation is the aluminium beverage can, hundreds of billions of which are produced annually.   Each can's naturally glossy surface makes as an attractive backdrop for the product name, and while its thin walls can withstand up to 90 pounds of pressure per square inch (three times that in a typical car tyre), the contents can be easily accessed with a simple pull on the tab.   And although aluminium refining gobbles up a large chunk of global electricity, aluminium cans can be recycled economically and repeatedly, each time saving almost 95% of the energy required to smelt the metal in the first place.

 

There is, however, a darker side to this shiny metal.   Despite its abundance in Nature, aluminium is not known to serve any useful purpose for living cells.   Yet in its soluble, +3 form, aluminium is toxic to plants.   Release of Al3+ from its minerals is accelerated in the acidic soils which comprise almost half of arable land on the planet, making aluminium a major culprit in reducing crop yields.   Humans don't require aluminium, and yet it enters our bodies every day - it's in the air we breathe, the water we drink, and the food we eat.   While small amounts of aluminium are normally present in foods, we are responsible for the major sources of dietary aluminium: food additives, such as leavening, emulsifying and colouring agents.   Swallowing over-the-counter antacids can raise intake levels by several thousand-fold.   And many of us apply aluminium-containing deodorants directly to our skin every day.   What's worrying about all this is that several studies have implicated aluminium as a risk factor for both breast cancer and Alzheimer's disease.   While most experts remain unconvinced by the evidence, aluminium at high concentrations is a proven neurotoxin, primarily effecting bone and brain.   So, until more research is done, the jury will remain out.   Now, perhaps that IS something to trouble your mind on your next long haul flight.

 

Chris Smith

Researcher Kira Weissman from Saarland University in Saarbruken, Germany with the story of Aluminium and why I haven't been saying it in the way that Humphrey David intended.   Next week, talking of the way the elements sound, what about this one.

 

Brian Clegg

There aren't many elements with names that are onomatopoeic.   Say oxygen or iodine and there is no clue in the sound of the word to the nature of the element, but zinc is different - zinc, zinc, zinc, you can almost hear a set of coins falling into an old fashioned bath.   It just has to be a hard metal.   In use, zinc is often hidden away, almost secretive.   It stops iron rusting, sooths sunburn, keeps dandruff at bay, combines with copper to make a very familiar gold coloured alloy and keeps us alive but we hardly notice it.  

 

Chris Smith

And you can catch up with the clink of zinc with Brian Clegg on next week's Chemistry in its Element.   I'm Chris Smith, thank you for listening and goodbye. 

 

     (Promo)

 

Chemistry in its elementis brought to you by the Royal Society of Chemistry and produced by thenakedscientists dot com. There's more information and other episodes of Chemistry in its element on our website at chemistryworld dot org forward slash elements. 

 

(End promo)

  Help text not available for this section currently
  Help Text

Resources

Description :
This experiment illustrates the displacement of copper from copper(II) sulfate solution using aluminium foil.
Description :
Aluminium is soft, lightweight and ductile with excellent thermal and electrical conductivity. It is highly reactive, though the metal is protected by a surface layer of inert transparent oxide (Al2O...
Description :
An introduction to the common elements found in the Earth's crust. This can be used to underpin topics on useful materials from the Earth and on the extraction of metals.
Description :
Gives information about the most common elements in the Earth’s crust and the other the chemical composition of some minerals.
Description :
The reaction between aluminium and iodine is catalysed by water. This is a spectacular demonstration as clouds of purple iodine vapour are produced.
Description :
Many elements react with chlorine on heating. The reactions and the properties of the products illustrate the periodic nature of the elements. The reactions require less energy input to initiate than...
 

Terms & Conditions


Images © Murray Robertson 1999-2011
Text © The Royal Society of Chemistry 1999-2011

Welcome to "A Visual Interpretation of The Table of Elements", the most striking version of the periodic table on the web. This Site has been carefully prepared for your visit, and we ask you to honour and agree to the following terms and conditions when using this Site.


Copyright of and ownership in the Images reside with Murray Robertson. The RSC has been granted the sole and exclusive right and licence to produce, publish and further license the Images.


The RSC maintains this Site for your information, education, communication, and personal entertainment. You may browse, download or print out one copy of the material displayed on the Site for your personal, non-commercial, non-public use, but you must retain all copyright and other proprietary notices contained on the materials. You may not further copy, alter, distribute or otherwise use any of the materials from this Site without the advance, written consent of the RSC. The images may not be posted on any website, shared in any disc library, image storage mechanism, network system or similar arrangement. Pornographic, defamatory, libellous, scandalous, fraudulent, immoral, infringing or otherwise unlawful use of the Images is, of course, prohibited.


If you wish to use the Images in a manner not permitted by these terms and conditions please contact the Publishing Services Department by email. If you are in any doubt, please ask.


Commercial use of the Images will be charged at a rate based on the particular use, prices on application. In such cases we would ask you to sign a Visual Elements licence agreement, tailored to the specific use you propose.


The RSC makes no representations whatsoever about the suitability of the information contained in the documents and related graphics published on this Site for any purpose. All such documents and related graphics are provided "as is" without any representation or endorsement made and warranty of any kind, whether expressed or implied, including but not limited to the implied warranties of fitness for a particular purpose, non-infringement, compatibility, security and accuracy.


In no event shall the RSC be liable for any damages including, without limitation, indirect or consequential damages, or any damages whatsoever arising from use or loss of use, data or profits, whether in action of contract, negligence or other tortious action, arising out of or in connection with the use of the material available from this Site. Nor shall the RSC be in any event liable for any damage to your computer equipment or software which may occur on account of your access to or use of the Site, or your downloading of materials, data, text, software, or images from the Site, whether caused by a virus, bug or otherwise.


We hope that you enjoy your visit to this Site. We welcome your feedback.

References

 
Images:  Visual Elements © Murray Robertson 2011
Mining and Sourcing data:  British Geological Survey – natural environment research council.
Text:  John Emsley Nature’s Building Blocks: An A-Z Guide to the Elements, Oxford University Press, 2nd Edition, 2011.
Additional information for platinum, gold, neodymium and dysprosium obtained from Material Value Consultancy Ltd www.matvalue.com
Data: CRC Handbook of Chemistry and Physics, CRC Press, 92nd Edition, 2011.
G. W. C. Kaye and T. H. Laby Tables of Physical and Chemical Constants, Longman, 16th Edition, 1995.
Members of the RSC can access these books through our library.